Radio signaling system



Nov. .24, 1931'. LP. BYRNES RADIO SIGNALING Filed Aug. 7, 1928 Inventor:

m r 9 w. B .t E A 9 .m .m H v W U0 b Patented Nov. 24, 1931 uNirsn srarss earsnr @FFECE IRVING-F. BYRNES, OF SCHENEC'IADY, NEW YORK, ASSIGNOR T GENERAL. ELECTRIC COMPANY, A CORPORATION 02' NEW YORK RADIO SIGNALING SYSTEM Application filed August 7, 1928. Serial No. 298,120.

My invention relates to radio signaling systems and more particularly to signaling systemsemploying goniometers for the purpose v of controlling radiation from radiobeacons 5 and the like.

In systems of the type indicated, which are now frequently used for directing airplanes, a pair of antennae are commonly em ployed, these antennae being arranged in dif ferent planes for projecting waves of equal intensity in different directions. The airplane may then pursue a course which is approximately midway between the planes of the two antennae in the area in which the signal intensity patterns of the two antennae overlap. This area is commonly called the equi-signal area, i. e., the area in which signals of equal intensity are received from both antennae. In order that the equi-sig- 2o nal line or area be a true criterion of the course which the airplane is to follow, it is necessary that the signal intensity pattern of the waves projected from the antennae should possess a certain degree of symmetry. Where the radiating antennae are excited from the windings of a goniometer as ordinarily constructed it has been found that the effect of inherent capacity existing between the windings of the goniometer is such that it impairs the symmetry of the signal intensity pattern and hence introduces errors in the course of the airplane, or other Vessel which is being directed.

7 It has heretofore been proposed to electrostatically shield the windings of the goniometer from each other thereby to eliminate the above undesirable effects. I have found, however, that somewhat better results may be had by introducing an electromot-ive' force 40 into each of the windings, as by an additional capacity coupling between the windings, in a manner such that the effect of this electromotive force is to neutralize the electromotive forces which are induced in either winding through the effect of the inherent capacity existing between the windings and thereby secureincreased accuracy in the direction of the equisignal area.

Accordingly one of the purposes of my invention is to provide the method means organization and method of operation, to-

gether with further objects and advantages thereof may best be understood by reference to the following description taken in connection with the accompanying drawings in which Fig. 1 represents a signaling system embodying my invention and Fig. 2 represents a goniometer which may be employed,

Referring to Fig. 1 of the drawings, I have shown at 1 and 2 a pair of antennae which are arranged at an angle with respect to each other and each of which are adapted to project the radiated wave in a direction at right angles to the plane of the antennae. These antennae are adapted to be supplied with high frequency currents from .a source 3 through a goniometer 4:. The vgoniometer A} is better shown in Fig. 2 and comprises a pair of secondary windings 5 and 6 which are arranged in planes which intersect each other-on the axis 7. These windings comprise the secondary or stator windings of the goniometer, the winding 5 being connected through suitable tuned circuits 8 and 9 to the antenna 1 and the winding 6 being connected through tuned circuits l0 and 11 .to the antenna 2. The primary windings 12 and 13 of the goniometer likewise are arranged in planes at an angle with respect to each other which intersect on the line 7 These windings are adapted to be alternately energized from a source 3 by means of any suit-able switching mechanism. For the purposes of illustration this switching mechanism is represented 'in the drawing as a simple double throw switch 1a the armature of which is connected to the source 3 and which is adapted alternately jto connect the windings 12 and '18 in circuit with the source 3. i The difi'erent primary and secondary windings of the goniometer are arranged preferably at right angles to each other although any other angle may be employed, as is desired. Under proper operating conditions when the primary winding 13, for example, is adjusted in the plane of Winding and winding 12 is energized a maximum current will be induced in the winding 5 and hence in he antenna 1 whereas no current will be induced in the winding 6 or antenna 2. Similarly when the winding 13 is energized, assuming that these windings be adjusted at right angles to each other, a maximum current will be induced in the winding 6 and no current will be induced in the winding 5. Different effects are, of course, produced when the windings are adjusted at different angles as is well-known in the art.

The above conditions are those which it is desired to obtain in the goniometer under ideal operating conditions, that is, it but one primary winding were employed and this winding were rotated within the secondary windings the currents in the secondary winding should vary cyclicly from zero to a maximum value, the maximum current occurring when the primary winding is in the same plane as the secondary winding and zero current occurring when the primary winding is at right angles to the secondary winding. Considerable diiiiculty, however, may be encountered in obtaining these conditions resulting from the inherent capacity which exists between the windings. It will be noticed from the structure of the goniometer as shown in Fig. 2 that considerable capacity is likely to exist between the secondary windings both at the top and at the bottom of the goniomet'er and that a certain degree of capacity coupling will exist between the primary and the secondary windings. Thus it will be seen that energy will be supplied from the primary winding into the secondary windings or from one secondary winding to the other due to these capacity effects and thu the desired current conditions in the antennae for producing desired symmetry of the signal intensity patterns will not be had.

In accordance with my invention a suitable impedance, such as a condenser 16, is con nected between a terminal of one of the secondary coils 5 and a terminal of the other secondary coil. While the operation of this impedance is not fully understood it is believed that its effect is to introduce an electromotive force from one winding into the other which is suflicient substantially to neutralize the effect of the electromotive force which is induced in that winding by the inherent capacity existing between the windings. For example, if we assume that the primary coils are at right angles to each other and in the planes of the secondary coils and that the coil 12 is energized, the maximum of electromotive force should exist in the Winding 5 and zero electromotive force should exist in the winding 6. Instead, however, a certain electromotive force will appear in the winding 6 due to the inherent capacity mentioned above, this electromotive force tending to cause a certain degree of undesired radiation from antenna. 2. The effect of capacity 16 appears to be to introduce an additional electromotive force in the winding 6 which is in opposed phase relation with that which is supplied to this winding through the inherent capacity with the result that the two electromotive forces tend to neutralize each other and therefore tend to reduce the current in the antenna 2 to zero. Similarly if the Winding 13 is energized an electromotive force will be supplied through the condenser 16 to the winding 5 which is sufficient to neutralize the electromotive force induced in that winding by the inherent capacity and accordingly the current in the antenna 1 may be reduced substantially to zero. Similarly if the coils are otherwise arranged the current in the secondary win dings will be maintained more nearly at the values resulting from the inductive relative of the windings. Of course, a certain degree of inherent capacity coupling will exist between the output circuit including the tuning devices 8 and 9 and the output circuits including the tuning devices 10 and 11, which will tend to have the same effect as capacity coupling between the windings of the goniometer. To overcome this effect each of the output circuits including each of the tuning devices are separately enclosed in conducting sheaths, these sheaths being represented by the dotted rectangles 17 and 18 in the drawings. By the use of these expedient-s I have found that considerably increased accuracy in the direction of the equi-sign al area may be had.

lVhile I have shown a single embodiment of my invention it will, of course, be understood that I do not wish to be limited thereto, since modifications may be made both. in the circuit arrangement and in the instrumentalities employed without departing from the spirit and scope of my invention as set forth in the appended claims. I

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. In a signaling system employing a goniometer hav ng intersecting secondary windings and a primary winding the method of overcoming the effect of inherent capacity existing between the secondary windings which includes the step of introducing an electromotive force into each of the secondary windings in opposed relation to the electromotive force in said winding resulting from said inherent capacity.

2. A radiating system having antennae arranged to project waves in directions at an angle to each other thereby to produce overlapping signal intensity patterns, a goniometer having intersecting windings, each of said windings being connected to one of said antennae, an additional winding in said goniometer in inductive relation with said intersecting windings, means for supplying high frequency current to said additional winding thereby to excite said antennae through the inductive relation of said windings and an impedance connected between the intersecting windings for aflecting the direction of the overlapping area of the sig nal intensity patterns.

3. The combination with a radio goniometer having a plurality of intersecting secondary windings and a primary winding arranged in inductive relation with the secondary windings, means for supplying high frequency current to the primary winding, and an impedance connected between the secondary windings to reduce the effect of in herent capacity between the windings.

4. The combination with a radio goniometer having a pair of secondary windings arranged in proximate space relation, a pri-- mary winding associated with each of said secondary windings, means for alternately energizing said primary windings and a. capacity connected between a terminal of one of said secondary windings and a terminal of the other secondary winding Whereby the effect of inherent capacity between the windings is reduced.

5. The combination with a radio goniometer having a pair of intersecting secondary windings and a primary winding arranged in inductive relation with said secondary windings and means for supplying electromotive force from one of said secondary windings to the other to neutralize the electromotive force induced in said other winding through the inherent capacity existing between the windings.

6. A radiating system having a. pair of antennae arranged to project waves in directions at an angle to each other thereby to produce overlapping signal intensity patterns, a goniometer having a pair of intersecting windings, an output circuit connecting each win ding with one of said antennae, means for alternately supplying energy to said windings, means for supplying electromotive force from one of said windings to the other to neutralize the effect of electromotive force induced in said other winding through in herent capacity existing between the windings and shielding means for reducing capacity efiects between the output circuits thereby to affect the direction of the overlapping area of the signal intensity patterns.

7. The combination with an inductance device having a plurality of windings, of means for alternately energizing said windings, and means for supplying an electromotive force from one of said windings to another to neutralize electromotive force induced in said other winding due to stray efi'ects existing between the windings.

8. The combination with an inductance device having a plurality of windings, means for energizing one and then another of said windings, and means for supplying an electromotive force to each windings to neutralize electromotive force induced therein through stray effects existing between the windings.

9. The combination with an inductance device having aplurality of windings, of

means for energizing one of said windings while another of said windings is substantially deenergized, and means for supplying an electromotive force to said other winding to neutralize electromotive force induced therein due to stray-effects existing between the windings.

10. An inductance device having a primary winding and a plurality of secondary windings, means including said primary winding for alternately energizing said secondary windings, and means for introducing an electromotive force in each of said secondary windings to neutralize electromotive force induced therein due to stray efiects ex isting between said windings.

In witness whereof, I have hereunto set my hand this sixth day of August, 1928.

IRVING F. BYR-NES. 

